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  • Antibody and DNA sensing pathways converge to activate the inflammasome during primary human macrophage infection.

Antibody and DNA sensing pathways converge to activate the inflammasome during primary human macrophage infection.

The EMBO journal (2019-08-31)
Larisa I Labzin, Maria Bottermann, Pablo Rodriguez-Silvestre, Stian Foss, Jan Terje Andersen, Marina Vaysburd, Dean Clift, Leo C James
ABSTRACT

Inflammasomes are potent innate immune signalling complexes that couple cytokine release with pro-inflammatory cell death. However, pathogens have evolved strategies to evade this cell autonomous system. Here, we show how antibodies combine with innate sensors in primary human macrophages to detect viral infection and activate the inflammasome. Our data demonstrate that antibody opsonisation of virions can activate macrophages in multiple ways. In the first, antibody binding of adenovirus causes lysosomal damage, activating NLRP3 to drive inflammasome formation and IL-1β release. Importantly, this mechanism enhances virion capture but not infection and is accompanied by cell death, denying the opportunity for viral replication. Unexpectedly, we also find that antibody-coated viruses, which successfully escape into the cytosol, trigger a second system of inflammasome activation. These viruses are intercepted by the cytosolic antibody receptor TRIM21 and the DNA sensor cGAS. Together, these sensors stimulate both NLRP3 inflammasome formation and NFκB activation, driving dose-dependent IL-1β and TNF secretion, without inducing cell death. Our data highlight the importance of cooperativity between multiple sensing networks to expose viruses to the inflammasome pathway, which is particularly important for how our innate immune system responds to infection in the presence of pre-existing immunity.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Nigericin sodium salt, ≥98% (TLC)
Sigma-Aldrich
CP-456773 sodium salt, ≥98% (HPLC)
Sigma-Aldrich
Anti-Adenovirus Antibody, Chemicon®, from goat
Sigma-Aldrich
Acridine Orange hydrochloride solution, ≥95.0% (HPLC), 10 mg/mL in H2O
Sigma-Aldrich
Deoxyribonucleic acid sodium salt from herring testes, Type XIV